Apparatus for recording the shrinkage temperature of leather, hides, skins, and the like



Sept. 21, 1954 w c APPARATUS FOR RECORDING T 0F LEATHER, HIDES,

Filed April 20, 1953 HTEL E SHRINKAGE TEMPERATURE SKINS, AND THE LIKE 2 Sheets-Sheet 1 Inventor WWW L; [Bunk A ltorney;

Sept. 21, 1954 K. WACHTEL 2,639,474

APPARATUS FOR RECORDING THE S'IRINKAGE TEMPERATURE OF LEATHER, HIDES, SKINS, AND THE LIKE Filed April 20, 1953 2 Sheets-Sheet 2 0 A fllilf 1 .33

Im'cnfur mum/kw By l A Hnrneys Patented Sept. 21, 1954 APPARATUS FOR RECORDING THE SHRINK- AGE TEMPERATURE OF LEATHER, HIDES, SKINS, AND THE LIKE Kurt Wachtel, Kingston Hill, England Application April 20, 1953, Serial No. 349,775

Claims priority, application Great Britain April 29, 1952 7 Claims.

As leather, hides and like materials shrink when heated beyond a critical temperature, which temperature varies with the nature of the leather and the processing or tanning treatments to which it has been subjected, it is necessary for leather manufacturers to know the shrinkage temperature of a hide, that is the temperature at which the hide commences to shrink, before the hide is used. The present day practice in the industry is to take one or more samples from a bale of hides, immerse it in water and raise the temperature slowly until initial signs of shrinkage are observed when the temperature of the water is taken. Such a procedure is not very reliable and is wasteful of the operators time, and it is the object of the invention to provide an apparatus which, once set into operation, can be left unattended if desired and will automatically cut off the heat supply when the leather sample commences to shrink whilst at the same time registering or recording the shrinkage temperature.

According to the invention apparatus for the purpose mentioned comprises means for supporting a specimen strip of leather or like material under slight tension within a body of liquid,

means for heating the liquid, a maximum thermometer or the equivalent responsive to the temperature of the liquid, a solenoid-operated valve or switch for controlling the heating means and means operatively associated with the specimen strip and adapted, immediately said strip com mences to shrink, to break the control circuit of the solenoid and thereby cut off the supply of heat to the liquid.

In order that the invention may be more fully understood reference will now be made to the accompanying drawings, wherein Fig. 1 shows more or less diagrammatically a first embodiment of the invention,

Fig. 2 is a similar view of a second embodiment, and

Figs. 3 and 4 are detail views showing two possible modifications of the arrangement shown in Fig. 2.

Referring first to Fig. 1, the apparatus shown comprises a vertically disposed panel I constituting a support for the control mechanism, a beaker or similar water vessel 2 adapted to be supported on a tripod or like stand 3 and a bunsen or similar gas burner 4 for heating the water in the vessel 2. Fixed to an extension of the panel I at the upper end thereof is a rigid metal frame 5 which is adapted to extend into the beaker and to the lower end of which is fitted a clip 6, a strip of leather 1 to be tested being attached at its lower end to said clip and at its upper end to a second clip 3 carried by a rod 9 suspended from one end of a beam iii. Preferably, an adjustable connection is provided between the clip 8 and rod 5, for example a hook II on the clip may engage selectively a number of spaced holes in the rod, to accommodate specimen strips of slightly different lengths. A maximum thermometer I2 is clipped to the frame 5 and a motor driven paddle or agitator 13 may be employed to circulate the water within the beaker and ensure that during heating there is an even increase in temperature throughout the whole body of water. The beam It is supported on a fixed Divot M and from its other end is suspended a rod l5 which extends through an aperture in one arm it of a bell crank lever l5, H and is threaded to receive an adjustable sleeve-like abutment IS. The arm it of the bell crank is fitted with an adjustable weight l9 which in use applies the desired tension to the leather strip i, whilst the other bell crank arm i 1 is formed with a lip 20 at its extremity adapted to engage the end of a lever arm 2| to retain it in a horizontal position. Fixed to the lever arm 2| is a mercury switch 22 which is interposed in the supply circuit of a solenoid 23 controlling a valve 24 in the gas supply line to the burner 4, the solenoid being energised to hold the gas valve open when the mercury switch is in the horizontal position shown.

The apparatus operates as follows:

Having suspended a specimen leather strip between the clips 3 and 8, the abutment I8 is adjusted on the rod it until the lip 28 on bell crank I! just engages the tip of lever arm 2| to hold it in the raised position and the weight [9 is also adjusted, if necessary, to apply a light tension on the strip. With the current switched on and the gas valve 24 open, the burner is ignited and the temperature of the water rises, the apparatus if desired being left unattended. Immediately the strip 1 commences to shrink the beam in is rocked so rocking the bell crank l6, l1 and releasing the lever arm 2|. The latter falls by gravity or under the action of a light spring, the solenoid circuit is broken at the switch 22 and the gas supply valve closes. Thus further heating of the water is stopped, the thermometer providing a record of the shrinkage temperature for immediate or future use.

Preferably, the motor l3a driving the paddle I3 is also controlled by the arm 2!, as for example, by a further switch carried on the arm,

Fig. 2 illustrates an alternative arrangement.

utilizing a different method of controlling the gas supply. The specimen strip l is suspended within a beaker of water with the aid of a frame- 5a and the beaker is heated by a bunsen burner: 4a as in the form previously described but in this instance the upper end of the strip 7 is attached to a cable 21 which passes around fixed pulleys ZBandis attached to a weight 29; The weight servesthedual function of applying-the desired tension to the-strip l and of forming part of a control switch as will now be explained. The burner 4a is fitted with a rotary control valve or tap provided with an elongated actuating arm 30 so arranged that when unobstructed it falls by gravity to the valve closing position. The arm 30 is adapted to be latched in the raised or valve open position shown on the drawing by a lever arm 3!, the latter carrying or embodying the armature 32 of a solenoid 33. The control circuit of the solenoid'includcs aswitch constituted bytheweight-Zll and a cooperating stationary but adjustable contact 34 and it will beseen that immediately the strip l commences to shrink the weight 29 is lifted so breaking the solenoidcircuit. Thereupon lever arm 3| falls releasing: the actuating arm 30 which in turn falls and closes the burner vlave. The solenoid circuit is preferably operated by abattery 35 or other low voltage source'to avoid sparking at the switch 29, .34'butas the paddle motor 113a is mains-operated a separate switch Sitfor controlling its. operation isattached to an extension of the lever arm 3| such that the motor is stopped when the leverv arm falls; A. small modification of the. above describe arrangement is'shown in Fig. 3 wherein the armature 32x18 mounted on the valvev actuating arm 30a, a shorter lever arm 3 la carrying the mercury switch 36 being latched in its operativeposition by the arm 30a. The manner of operation-will beapparent from the drawing. Azsecond modification of the lever control system is to secure a double-armed lever to the spindle ofthe burner valve or tap, one of the lever" carrying the armature and the other arm carrying the paddle motor control switch.- With this arrangement the solenoid-when energised holds the lever in a horizontal position with the valve or tap open and the control switch closed, deenergising of the solenoid permitting the lever to rotate under the action-of gravity or of a biasing spring to a position to'close the valve and open said-control switch.

Fig. 4 show-s a further variation of the arrangement illustrated in Fig. 2 wherein theweight 29-- is dispensedwith, the cable 2i being attached to a spring blade 3'! which normally-bearsagainst a stationary but adjustable contact 38, the spring blade applying the desired tension to the strip'l. The elements 31, 38 are connectedinto the solenoid circuit so as to constitute a switch, equivalent to-the switch 29, 34' of Fig. 2, and it will-be seen- 4 that by proper adjustment of the contact 38 it is possible to obtain a breaking of the solenoid circuit immediately the strip 1 commences to shrink.

It is to be understood that the embodiments described are given by Way. of example only and many other-variations are possible. Thus the falling movement of the lever arm 2|, 3"l'or Sla may be used to close a switch to actuate a bell or other aural or visual signalling device and so indicate the completion of the test. Again, although a. gas/burner is particularly suitable for use in this apparatus in that the generation of heat ceases immediately the gas supply is cut, immersion and other electrical heaters having this property are now obtainable and may be used if desired. Other forms of recording thermometers mayalso be used in the place of the maximum thermometer.

Finally, it may be mentioned that whilst most leathers have a shrinkage temperature within the rangerof 30 C. in some cases-it exceeds the boiling point of water. and insuch instancesthe wateris substituted by a: higher boiling point.

liquid.

I claim:

1. Apparatus for the purpose mentioned.com.- prising means 1 for supporting. a specimen strip of leather or like material under slight tension withina-body ofliquid, means for heating the. liquid,

break the control circuit. of the solenoid. and.

thereby cut off the supply. of heat to the liquid.

2: Apparatus as claimed in claim- 1, wherein. the specimen strip is suspended-between a fixed frame and-,one-end of. an oscillatable beam, the other end'of said beamhavingan operative connection with a lever system which applies the desired tension to. the strip, and which, when the beam-is rocked/by shrinkage of the specimen.

strip-, trips .a switch to break the solenoid circuit.

3; Apparatus as claimedin claim 2,,wherein a.v

rod. is attached to said other end of the beam andhas; an adjustable abutment thereon. engaging one arm of a weighted bellcrank lever which through said rod and beamtensions the. specimen strip, the. solenoidrbeing, controlled. bya mercury switch which is carried by a-lever. arm. latched in its operative position by the other arm of said bell crankv andadaptedwhenrev leased to fall and open said switch.

4. Apparatus as claimed-iniclaim.-l,,wherein the specimen strip is suspended .betweenafixed frame. and a cable attached-to. a..weight. operableto.

tension. the. strip, said weight co-acting, witha fixed contact to form-aswitch in the solenoidicir.

cuitsuch thatv shrinkage of saidstrip. lifts .the weight to open the solenoid circuit.

5. Apparatus .asuclaimed in .claim 4 and-wherein the body of liquid is. heated by; a. gas burner,. including an elongated actuating arm .on the valve,

or. tap of. said. burner and a pivoted .lever. -arm which carries-or embodies .the armature. of. the. solenoid. device and which,- when the. solenoid: is.. energised, la.tches theactuating armin the valve. openposition; saidactuating. arm. being released when the solenoid circuit is..broken..andl fal1ing. automatically. to a.position to shutoff the gas.

supply. to. theburner.

6. Apparatus as claimedincl'aimeland wherein.

cluding an elongated actuating arm on the valve or tap of said burner which arm carries or embodies the armature of the solenoid device, the arrangement being such that when energised the solenoid holds said arm in the valve open position but when the solenoid circuit is broken the arm falls or moves automatically to a position to shut ofi" the gas supply to the burner.

'7. Apparatus as defined in claim 1, wherein said means operatively associated with the specimen strip to break the control circuit of said solenoid comprises a cable connected to the specimen strip, a resilient spring blade which is connected to said cable and applies the tension to the specimen strip, and a fixed contact co-acting with said spring blade to form a switch in said solenoid circuit and operable to break said circuit upon shrinkage of the specimen strip.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,299,867 Wolfson Oct. 27, 1942 2,552,085 Budd May 8, 1951 2,635,456 Barstow Apr. 21, 1953 FOREIGN PATENTS Number Country Date 514,484 Great Britain Nov. 9, 1939 

